You would think that magicians, of all people, would appreciate a well-executed and harmless deception. More proof that no matter who you are, nobody likes being the butt of the trick...
Why shouldn't private groups be permitted to be male-only? There are plenty of female-only groups out there.
As soon as a male space allows women in, its character changes. It is good that there are still spaces for men and spaces for women and mixed spaces, if you ask me.
As for the immorality of deceiving a bunch of professional magicians, spare me. Literally no harm was done.
But when there is no proper alternative for a man or woman to join a similar club, it's more about the exclusion of people with the same interest but happen to have the wrong sex.
Men should be moved to their own separate social and professional clubs, where they can't disenfranchise anybody.